Add changelog, bug tracker and other urls to metadata and force 2fa for releases (karafka#306)

- Change contact email for dev maintenance
- Add metadata and provide direct changelog URL, source uri and others to rubygems metadata
- Enforce mfa for releases

Author: mensfeld

rdkafka.gemspec

@@ -4,7 +4,7 @@ require File.expand_path('lib/rdkafka/version', __dir__)
 
 Gem::Specification.new do |gem|
   gem.authors = ['Thijs Cadier']
-  gem.email = ["[email protected]"]
+  gem.email = ["[email protected]"]
   gem.description = "Modern Kafka client library for Ruby based on librdkafka"
   gem.summary = "The rdkafka gem is a modern Kafka client library for Ruby based on librdkafka. It wraps the production-ready C client using the ffi gem and targets Kafka 1.0+ and Ruby 2.4+."
   gem.license = 'MIT'
@@ -29,4 +29,14 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency 'simplecov'
   gem.add_development_dependency 'guard'
   gem.add_development_dependency 'guard-rspec'
+
+  gem.metadata = {
+    'funding_uri' => 'https://karafka.io/#become-pro',
+    'homepage_uri' => 'https://karafka.io',
+    'changelog_uri' => 'https://github.com/karafka/rdkafka-ruby/blob/main/CHANGELOG.md',
+    'bug_tracker_uri' => 'https://github.com/karafka/rdkafka-ruby/issues',
+    'source_code_uri' => 'https://github.com/karafka/rdkafka-ruby',
+    'documentation_uri' => 'https://github.com/karafka/rdkafka-ruby/blob/main/README.md',
+    'rubygems_mfa_required' => 'true'
+  }
 end